UK switches to Merck's Gardasil for HPV vaccination

LONDON (Reuters) - Britain is to stop using GlaxoSmithKline's cervical cancer vaccine Cervarix from next September and will instead offer girls Merck & Co's rival product Gardasil.

The move underscores Gardasil's lead in a $1 billion-plus worldwide market for vaccines that protect against the sexually transmitted human papillomavirus (HPV), which can cause cervical cancer.

The health ministry said on Thursday the decision followed a competitive tendering exercise. GSK, however, said it had opted not to bid in the process because the government had made clear it wanted a vaccine offering broader protection.

While both shots are effective, Gardasil targets four strains of HPV -- two responsible for cervical cancer and two causing the less serious condition of genital warts -- while Glaxo's product addresses only the two cancer strains.

Following a review of the various conditions caused by HPV, British health authorities placed additional emphasis on genital warts in the 2011 tender, effectively knocking Cervarix out of the competition.

David Salisbury, the government's director of immunization, said experts had weighed up both the cost and clinical benefits before deciding to switch to Gardasil.

"We have reflected the changes in scientific knowledge that has become available since last time," he told reporters.

"They are not huge changes -- we still prioritize the prevention of cancer -- but based on all these things the winner is Gardasil."

Gardasil protects against the two strains of HPV virus that cause more than 70 percent of cervical cancer and two types that cause 90 percent of genital warts.

GIRLS AGED 12-13

Under the British program, HPV vaccination is offered routinely to girls aged 12 to 13 years, with a catch-up program for those up to 18.

Cervarix, from British-based GSK, has been the vaccine of choice since the program was started in 2008 -- but a number of critics said at the time that the decision was based on cost and Gardasil should have been chosen from the start.

Tony Falconer, president of the Royal College of Obstetricians and Gynaecologists said he was delighted about the decision to switch to the quadrivalent vaccine.

"Not only will it provide immunity against cervical cancer caused by HPV, it will also protect against the strains of HPV that cause genital warts, which are unpleasant and the cause of much psychological distress for sufferers," he said in a statement.

Gardasil is sold in Europe by Sanofi Pasteur MSD, a joint venture between U.S.-based Merck and French drugmaker Sanofi. A spokesman for Sanofi Pasteur MSD declined to comment on the price it was charging the British government.

Globally, Gardasil outsells Cervarix, with revenues of $988 million last year and sales expected to reach $1.25 billion by 2015, according to Thomson Reuters Pharma data. Cervarix sales last year were 242 million pounds ($375 million) and are forecast to reach $848 million in 2015.

GSK said at least 5 million doses of Cervarix had been administered in Britain up to July 2011 and the company remained committed to making the vaccine available around the world.

Significant new demand for HPV vaccines could soon open up in the poor nations, following a decision last week by the GAVI international immunizations group to fund their roll-out in developing countries -- provided it can reach a deal on pricing with the manufacturers.